The present invention generally relates to the field of pyrotechnic initiators, and more particularly to a pyrotechnic initiator with an output can that has an encapsulation material retention feature.
Pyrotechnic initiators have many uses in industrial and consumer applications. One important use is in triggering the inflation of airbags in motor vehicles. Significant efforts have been made in the automotive industry to reduce the cost of manufacturing reliable airbag initiators, but there remains a need for further reduction in the costs of manufacturing reliable initiators.
In particular, initiators have been made with an encapsulation of insulator material such as nylon. In existing encapsulated initiator designs, secure adherence of the encapsulation material to the body of the initiator may be enhanced through a retention feature on the header assembly called a backdraft. There are several disadvantages with the backdraft, however. First, the backdraft is applied through an expensive machining operation. Second, if the initiator contains onboard circuitry, the backdraft requires that the output can be held flush with the header to a tight tolerance after welding so as to prevent shorting of the circuitry. Third, the amount of encapsulation material captured by the backdraft is limited by the space available on the header assembly. Fourth, with a backdraft, weakness in the weld can make the output can prone to ejecting upon firing of the initiator.
Thus, there remains a need for improving the manner of retention of encapsulation material to the initiator body in encapsulated initiators. In this regard, it is believed that an encapsulation material retention feature has never been provided on the output can of an initiator.